3204.12.50.90 - Other

This HTS category, 3204.12.50.90, encompasses "Other" synthetic organic coloring matter that falls under the umbrella of acid dyes, whether or not premetallized, and mordant dyes, and their preparations. These are coloring agents that are typically applied from an acidic dye bath and form ionic bonds with fibers that contain basic functional groups, such as wool, silk, nylon, and modified acrylics. This broad category serves as a residual grouping for acid and mordant dyes that are not specifically enumerated or identified by their Chemical Abstracts Service (CAS) registry numbers within preceding subheadings.

To understand what falls into this "Other" classification, it's crucial to differentiate it from its sibling categories. The sibling entries, such as FD&C red 40, FD&C yellow 5, and FD&C yellow 6, represent specific, widely recognized synthetic organic dyes that are often used in food, drug, and cosmetic applications. These are listed separately due to their distinct identities, common usage, and often specific regulatory considerations. Therefore, 3204.12.50.90 is intended for acid dyes and mordant dyes that do not correspond to these named examples and are not otherwise specifically classified.

As this is a leaf node in the HTS classification structure, there are no further subcategories to introduce. Classification within this subheading relies on a process of elimination: if a synthetic organic coloring matter is identified as an acid dye or a mordant dye, and it is not one of the specifically listed FD&C colors (or another explicitly named dye in a preceding sister classification), then it will fall under this residual "Other" designation. Importers and customs brokers should meticulously review the chemical composition and intended application of the dye to ensure it meets the definition of an acid or mordant dye and does not fit into any more specific HTS code.